Problem: All of Luis's friends wanted to try the candy bars he brought back from his trip, but there were only 9 candy bars. Luis decided to cut the candy bars into pieces so that each person could have $\frac{3}{5}$ of a candy bar. After cutting up the candy bars, how many friends could Luis share his candy with?
Answer: We can divide the number of candy bars ( $9$ ) by the amount Luis gave to each person ( $\frac{3}{5}$ of a bar) to find out how many people he could share with. $ \dfrac{{9 \text{ candy bars}}} {{\dfrac{3}{5} \text{ bar per person}}} = {\text{ total people}} $ Dividing by a fraction is the same as multiplying by the reciprocal. The reciprocal of $\dfrac{3}{5} \text{ bar per person}$ is ${\dfrac{5}{3} \text{ people per bar}}$ $ {9\text{ candy bars}} \times {\dfrac{5}{3} \text{ people per bar}} = {\text{total people}} $ ${\dfrac{45}{3}\text{ people}} = 15\text{ people}$ By cutting up the candy bars, Luis could share his candy with 15 of his friends.